Blasthead structure for tempering glass sheets



Nov. 21, 1967 A. McMASTER 3,353346 BLASTHEAD STRUCTURE FOR TEMPERINGGLASS SHEETS Filed July 29, 1964 4 Sheets-Sheet 1 INVENTOR.

a? HAHULDA.MUMASTEH.

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Nov. 21, 1967 H. A. MGMASTER BLASTHEAD STRUCTURE FOR TEMPERING GLASSSHEETS H mm 2 -N-E 2 a WM 8 w v h m A M Q Q n 4 a m mu. 4 l 9 2 y m & &mm \m d w. n

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Nov. 21, 1967 H. A. MCMASTER 3,353,946-

BLASTHEAD STRUCTURE FOR TEMPERING GLASS SHEETS Filed July 29, 1964 4Sheets-Sheet 5 L INVENTOR:

HARULDAMuMAETER.

.ATTYS- United States Patent 3,353,946 BLASTHEAD STRUCTURE FOR TEMPERINGGLASS SHEETS Harold A. McMaster, Woodvilie, Ohio, assignor toPermagiass, Inc., Woodville, Ghio, a corporation of Ohio Filed Jan. 29,1964, Ser. No. 341,050 11 Claims. (Cl. 65-348) The present inventionrelates to apparatus comprising opposing b lastheads for directing atempering fluid against opposite sides of a sheet of material; and moreparticularly to apparatus comprising opposing blastheads which direct acooling fluid against opposite sides of a sheet of glass that is hung bystructure secured to the top portion of the sheet in a manner permittingthe sheet to swing laterally between the opposing blastheads.

An object of the present invention is the provision of new and improvedapparatus having opposing blastheads for directing a fluid againstopposite sides of a sheet of material, and which apparatus automaticallydamps oscil- 'latory movement of the sheet between the opposingblastheads.

Another object of the invention is the provision of new and improvedopposing blasthead structures between which a sheet of material isplaced, and each of which has pressure areas that are separated fromexhaust areas by weir structures which project toward the sheet mate--paratus having opposed blasthead structures between which a sheet ofmaterial may be suspended for fluid treatment, which apparatus willautomatically and rapidly center the sheet between said opposedblastheads due to forces created by fluid pressure in the areas on eachside of said sheet and the adjacent blasthead.

A further object of the invention is the provision of a new and improvedblasthead structure of the above described type having uniformly spacednozzles connected by integral webs and which nozzles and webs are moldedfrom a resilient elastomeric material to form a shock absorbing bumper.

A still further object of the invention is the provision of aninexpensive blasthead structure of the above described type wherein thenozzle portions of the molded nozzle and web sections are provided withprojections which are forced through holes in the face plates of plenumchambers and which projections thereafter expand to engage the back sideof the face plates to hold the molded nozzle and web sections in place.

Further objects and advantages will become apparent to those skilled inthe art to which the invention relates from the following description ofa preferred embodiment described with reference to the accompanyingdrawings forming a part of this specification, and in which:

FIGURE 1 is a side view in elevation of a blasthead structure which ispositioned below a furnace to receive sheets of glass therefrom andwhich embodies the present invention;

FIGURE 2 is a plan view of the blasthead structure shown in FIGURE 1taken approximately from the position indicated by the line 22 of FIGURE1;

FIGURE 3 is an isometric view of one of the two 3,353,946 Patented Nov.21, 1967 "Ice - approximately from the position indicated by the line 55of FIGURE 3, showing combination nozzle and weir sections installed onthe front of the plenum chamber which faces the glass; and

FIGURE 6 is a greatly enlarged fragmentary cross section taken along theline 66 of FIGURE 5.

While the invention may be otherwise embodied, it is herein shown anddescribed as embodied in a blasthead structure for cooling large sheetsof glass which may vary in size. The blasthead structure 10 is shown inFIGURE 1 as being positioned below a furnace 11 that is supported on asteel structure 12 having four legs 13 positioned outwardly of theblasthead structure It). The furnace has a floor 14 with a long narrowopening 15 therein through which glass sheets, one of which isdesignated by the reference number 16, hung from a supporting carriage17, are raised and lowered. The supporting carriage 17 comprises alength of pipe 18 having a plurality of tongs 19 which grip the upperedge of the sheet of glass 16 for supporting it both in the furnace 11and in the blasthead structure 10. A pair of spaced apart T-sections 20project upwardly from opposite ends of the pipe 18.

The supporting carriage 17 is raised into and lowered out of the furnace11 by means of a lift structure 21 comprising a vertical shaft 22 havinga horizontal leg 23 on its bottom end. The horizontal leg 23 has a pairof L-shaped fingers 24 at each of its ends with the horizontal legs ofeach pair of fingers 24 projecting toward each other and arranged toengage the bottom surface of the top horizontal portion of theT-sections 20 to lift the supporting carriage 17i The supportingcarriage 17 is adapted to rest upon a series of rollers 25 when thesheet of glass 16 is properly positioned in the blasthead structure 10,and the series of rollers 25 extend laterally of the blasthead structure10 to a loading and unloading station, not shown. Coupling of thesupporting carriage 17 onto the lift structure 21 is accomplished bymoving the supporting carriage 17 laterally until the' horizontal legs23 of the L-shaped fingers 24 are underneath the bottom of thehorizontal portions of the T-sections 20.

The blasthead structure 10 has two sections 26 and 26' which aresubstantially identical excepting that they are mirror images of eachother. Only one of the sections will be described in detail, and thoseportions of the other section which are substantially identical will bedesignated ,by a like reference numeral characterized further in that aprime mark is affixed thereto.

The blasthead section 26 comprises a plenum box 27 that is formed intWoidenti-cal half sections 28 which are joined by a center plate 29(see FIGURES 3 and 4). The rear end of each half section 28 is formed bya vertically'extending rectangular channel section 30 having a. flatrear abutment surface 31. The flat rear abutment surfaces 31 slidinglyand sealingly abut the flat front surfaces of respective rectangularflanges 32 (see FIG- ure 2) which form the front end of air supply ducts33. The small rear ends of the supply ducts 33 are connected to thedischarge'of respective ones of a pair of fans 34 by flexible ductsections 35 and shutoff valves 36 (see FIGURE 1). The fans 34 are drivenby individual electric motors 37 and V-belt drives 38.

Each shutoff valve 36 comprises a plurality of louvers, not shown, whichare opened and closed by a lever 39. The levers 39 and 39' are actuatedby structure which will open and close all valves 36 and 36'simultaneously. Cross shafts 40 and 40 are positioned beneath the valves36 and 36' respectively, and each end of the respective shafts areprovided with arms 41 and 41' which are connected to the levers 39 and39' by connecting bars 42 and 42'. Sprockets 43 and 43' are fixed to therear ends of the shafts 40 and 40 respectively, and these sprockets areconnected together by an endless chain 44 kept taut by idlers 45. Shaft40 is provided with an actuating arm 46 (see FIGURE 1), and the arm 46is in turn moved by the piston rod 47 of a hydraulic cylinder 48.

The half sections 28 of the plenum box 27 are substantially identical,but are of opposite hand, and are connected by the center plate 29 (seeFIGURE 3). The front face of each of the sections 28 has four identical,vertically spaced rectangular face plates 49, the inner ends of whichare fixed to the center plate 29, and the outer ends of which are fixedto side plates 50. The face plates or end walls 49 are evenly spacedvertically to provide rectangular voids defining exhaust means orexhaust openings 51. The front faces of the sections 28 also includeupper and lower face plates 52 and 53 which have a vertical dimensiongreater than that of the face plates 49, and which are separated fromadjacent face plates 49 by distances forming exhaust areas 51 there'-between which are identical in area with the exhaust areas 51 betweenthe face plates 49. A generally trapezoidal top plate 54 extends fromthe top edge of the upper faceplate 52 to the top of the channel 30, anda similar bottom plate (not shown) extends from the bottom edge of thelower face plate 53 to the channel section 30 to close off the top andbottom of the sections 28, respectively. Individual ones of a pluralityof identi cally shaped, horizontal cross plates 55 extend rearwardlyfrom the lower horizontal edge of the upper face plate 52, the edges ofthe horizontal face plate 49 and the upper edge of the lower face plate53 to the channel section 30 in parallel spaced planes to form parallelplenum chambers 56 (see FIGURE 6) separated by exhaust passages 57leading to the open areas 51 (see FIG- URE 3). The rear corners of thecross plates 55 adjacent the rectangular channel section 30 aretriangularly notched (see FIGURE 4), and short vertical spacing plates58 and 59 extend horizontally across between opposite sides of thechannel section 30 and vertically between the plates 55 across theexhaust passage 57 to prevent air from the channel section 30 fromflowing into the exhaust passages 57..Conversely, vertical side plates60 (see right side of FIGURE 4) extend between the side edges of the topplate 54 and the next lower cross plate 55, between the edges of crossplates 55 that are connected by the face plates 49 and between thebottom plate (not shown) and the lowermost cross plate 55 to close offthe sides of the plenum chambers 56. In each of the sections 28 airflows from the vertically extending opening defined by the channelsections 30 and the verticalspacing plates 58 and 59 and divert it intothe horizontal, spaced apart plenum chambers 56.

Air from the plenum chambers 56 is projected against the surface of thesheet of glass 16 through a. plurality of uniformly spaced nozzles 61(see FIGURES and 6) that are mounted in the face plates 49. The faceplates 49 are tall enough for six horizontal rows of nozzles 61.According to the invention, horizontal weirs or baffles 62 (see FIGURE5) extend along the upper and lower edges of the face plates 49 towardthe glass to define pressure areas and to separate these pressure areasfrom the intervening exhaust areas 51. Air discharged from the nozzles61 in the central region of the plates 49 must pass vertically throughelongated spaces indicated by the reference numbers 63 (FIGURE 6)between the glass 16 and weirs 62 causing a slight back pressure toexist in the area between the weirs 62. Such air flow is shown by thearrows in FIGURE 6.

According to a preferred arrangement, the weirs 62 are formed as websbetween the uppermost and lowermost horizontal rows of nozzle n in 9face Plate 49. The webs and nozzles 61 are preferably integrally moldedfrom an elastomeric material such as rubber which will act as aresilient cushion should the sheet of glass 16 strike the nozzles orwebs. Inasmuch as the sheets of glass to be cooled will not always be aswide as the plenum box 27, spaced apart baflies 64 extend verticallybetween the horizontal weirs 62 to prevent air from flowing laterallybetween the horizontal weirs 62 without creating a back pressure.Inasmuch as there are four rows of nozzles 61 between the top and bottomweirs 62, and the nozzles 61 are spaced on a square pattern, thepreferred baflles and nozzle construction comprises four nozzles 61connected together by the webs 64. Each of the end nozzles 61 of thegroup has a half web 65 pro jecting therefrom in line with the webs 64.By aligning the half-webs 65 along the top and bottom edges of theplates 49, solid weirs 62 are formed. In addition, the same structurescan be arranged vertically to provide a plurality of baffles whichrestrict lateral flow of air between the weirs 62 and aid in providingpressure buildup between the glass 16 and plates 49. The nozzles 61 aresupplied with air from the plenum chambers 56 through openings 66 in thefront plates 49. While various means can be used to hold the web andnozzle structures in place, the preferred arrangement has flangedprojections 67 (see FIGURE 6) on the inner end of the nozzles 61, whichextend through the openings 66 and the laterally turned portions ofwhich abut the back side of the plates 49 surrounding the openings 66.The nozzles 61 preferably also have flanges 68 which abut the front faceof the plates 49 to add lateral stability to the web and nozzlestructures when they are installed in place on the plates 49.

The same molded web and nozzle structures are installed horizontallyalong the bottom edge of the upper face plate 52 and at the sixth row ofholes 66 upwardly from the bottom edge of plate 52. Additional web andnozzle structures are arranged vertically between the bottom and sixthrows, as seen in FIGURE 5. Partial sections of the web and nozzlestructures are arranged vertically above the sixth row, previouslyreferred to, to provide a uniform pattern of air distribution adjacentthe top edge of the plate 52. The lower face plate 53 has web and nozzlestructures installed thereon in the same general manner as has plate 52excepting that the pattern is opposite hand.

In order that a uniform pattern of air distribution will be providedagainst the glass sheet 16 opposite the exhaust areas 51, a second typeof molded nozzle structure 69, best seen in FIGURE 6, is provided. Thenozzle structure 69 is a generally T-shaped molded structure, with thecross bar extending vertically to engage the bottom and top cross plates55 of opposing plenum chambers 56. Holes 66a are provided in the plate55, and the opposite ends of the cross bars of the T-shaped structures69 are inserted therein with their flanges 67a gripping the innersurfaces of the plates 55. Each of the T-shaped structures 69 has a pairof generally L-shaped nozzle openings 70, each of which extends throughone of the flanges 67 and projects forwardly to terminate in the planeof the ends of the nozzles 61 in the same reticulated pattern.

The plenum boxes 27 that are positioned on opposite sides of the glasssheet 16 are substantially identical but are mirror images so that thepressure areas formed over the plates 49 by the weirs 62 and webs 64 aregenerally opposite each other, as are the exhaust areas 51. When a sheetof glass 16 is brought between the opposite blasthead structures, airfrom the nozzles 61 must flow over the weirs 62 to the exhaust areas 51.When a sheet of glass 16 is moved toward one of the blastheads, as by avagrant air current or during its travel into or out of the spacebetween theblastheads it decreases the clearance spaces 63 between theweirs 62 and the glass to choke off air flow to the exhaust areas 51 andto increase the pressure between the plates 49 and the glass. At thesame time, the clearance space 63 between the glass 16 and the weirs 62of the opposing blasthead is increased so that the pressure between theglass and the corresponding plates 49 of the opposing blasthead isdecreased. This increase in pressure on one side of the glass, anddecrease in pressure on the other side causes the glass to move backtoward center. Any movement from an off-center position between theblastheads is therefore automatically opposed, so that any swinging oroscillating movement of the sheet of glass between the blastheads israpidly damped.

The nozzles 61 and 70 cause air to impinge upon the glass and sweep awaythe layer of warm air adjacent the sheet of glass 16 which wouldotherwise reduce the rate of cooling of the glass. Air from each nozzleimpinges on a definite area of the glass, and in order that the air fromthe nozzles will be caused to impinge upon all areas of the glass, theplenum boxes 27 and 27' are caused to oscillate to move the nozzles in acircular pattern.

The top ends of the side plates 50' (see FIGURE 1) of the plenum boxes27 and 27' are provided with brackets 71 which extend laterallyoutwardly in opposite directions, and the bottom ends of the side plates50 are provided with similar brackets 72 which also extend laterally,outwardly beneath the brackets 71. Upper crank shafts 73 arehorizontally supported in line with the brackets 71 and 71 at oppositesides of the plenum boxes 27 and 27, and lower crank shafts 74 arehorizontally supported in line with the brackets 72 and 72'. Each of thecrank shafts 73 and 74 is provided with double throws 75 which areidentically angularly positioned and each of which receives a bracket 71and 71' or receives a bracket 72 and 72, as the case may be. Thecrankshafts 73 and 74 therefore position the plenum boxes 27 and 27'directly opposite each other, and the crankshafts 73 and 74 carrycounterweights 76 which oflset the weight of the plenum boxes 27 and27'. The plenum boxes 27 and 27' are oscillated by a drive comprising asprocket 77 (see FIGURE 2) fixed to one of the lower crankshafts 74. Thesprocket 77 is driven by a chain 78 and sprocket 79 fixed to a jackshaft 80, and the jack shaft 80 is in turn driven by a sprocket andchain drive mechanism 81 powered by a motor 82.

Operation of the motor '82, therefore, drives one of the crankshafts 74which oscillates the plenum boxes 27 and 27'. The four crankshafts 73and 74 turn together causing the plenum boxes 27 and 27 to translate ina circular path. During movement of the plenum boxes 27 and 27' thesurfaces 31 slide over the faces of the flanges 32 to maintain a sealtherebetween.

When the lift structure 21 lowers a carriage 17 onto the rollers 25 toposition a sheet of glass 16 between the opposing sections of theblasthead structure 10, the cylinder 48 is actuated to open valves 36and 36' to cause air from the fans 34 and 34' to flow through nozzles61, 61' and 70, 7 At the same time the motor 82 is started to oscillatethe plenum boxes 27 and 27' to evenly distribute the blast from thenozzles over all parts of the sheet of glass 16. Air from most of thenozzles 61 and 61 must flow over weirs -62 to the exhaust areas 51 andout through the passages 57; and if the sheet of glass 16 moves towardone plenum chamber, it chokes off air flow over the weirs 62 and 62' asthe case may be. This reduces flow through the nozzles 61 or 61 as thecase may be that supply air to the pressure areas which are choked offto decrease the pressure drop through the nozzles 61. Inasmuch as thepressure in the plenum chamber 56 is considerably above atmospheric, thedecrease in flow through the nozzles rapidly builds up pressure withinthe space between the weirs, glass and the face of the blasthead toforce the sheet of glass away from the blasthead toward which the glasshad moved. As the glass moves toward one plenum box it moves away fromthe opposite plenum box to decrease pressure on the opposite side of theglass to cause the sheet of glass to move back toward a center position.Swinging movement between the blastheads is therefore rapidly damped.

By way of example, in one embodiment of the invention, the nozzles 61are /2" in diameter and are located on a 2" square pattern, and theweirs 62 project to within 2" of the center position of the glass. FromFIG. 5 it can be seen that air from the six nozzles in each vertical rowon plate 49 will divide so that three nozzles exhaust upwardly to anexhaust area 51 while three nozzles exhaust downwardly to an exhaustarea 51, so that the air from 2 /2 nozzles must pass between the glassand the weirs 62 through an area 2" x 2" or 4 square inches. Thecombined cross sectional area of 2 /2 nozzles equals 0.5 square inch, sothat the velocity of the exhaust air over the weir equals 0.5 divided by4 or 0.125 times the velocity of the air through the nozzles.

The kinetic energy of a moving fluid is proportional to the square ofits velocity, and the pressure drop across a flow restriction istherefore a function of the square of the change in velocity across theflow restriction. The pressure at the weir is then (.125) squared or0.0156 times the pressure drop in the nozzles, neglecting the entrancelosses. If the plenum pressure is 10 inches of water, the pressure dropin the nozzles will be 9.85 inches of water, and the exhaust backpressure across the weir will be 0.15 inch of water.

Assuming that the glass 16 moves /2 inch off of its center positiontowards one set of nozzles 61 and weirs 62, the exhaust area becomes 2inches x 1 /2 inches or 3 square inches and the velocity becomes 0.5divided by 3 or 0.167 times that in the nozzles. The back pressureacross the weir then becomes 0.0278 times the pressure drop in thenozzles or 0.27 inch of water. This is an increase of 0.27 minus 0.15which equals 0.12 inch of water.

At the same time the other side of the glass has moved /2 inch furtheraway from the adjacent weirs 62, so that the exhaust area with respectthereto is 5 square inches to provide a velocity across the weir whichequals 0.5 divided by 5 or 0.1 times that in the nozzles. This gives aback pressure of only 0.10 inch of water across the weir or a decreaseof 0.15 inch minus 0.10 inch or 0.05 inch of water. The combined changein back pressure which tends to center the glass therefore equals 0.05inch 0.12 inch or .17 inch of water 'which equals 0.815 pound per squarefoot. Since there is substantially no change in back pressure over theexhaust areas 51 (see FIG. 5), the centering pressure covers only of thetotal area of the glass to give an average of 0.55 pound per square footof glass area which is more than sufiicient to cause the glass to assumea centered position. In other words, the fluid is ejected from therespective nozzles to impinge a sheet of glass at a relatively highvelocity to provide a high heat transfer rate between the glass and thefluid since the large volume of fluid impinges and leaves the sheet.Thereafter, the fluid returns and flows between the nozzles at arelatively low velocity, thereby providing a static pressure in eachcompartment. The fluid flows at the relatively low velocity to a weirwhere the fluid is restricted as it flows over the weir at a velocitywhich is higher than the low velocity in the compartment but lower thanthe velocity of the fluid ejected from the nozzles. As the fluid isrestricted in passing over each weir, the static back pressure in eachcompartment is provided for centering a sheet between the blastheads.

When the glass 16 has been cooled, the carriage 17 is slid across therollers 25 to the unloading position, the motor 82 is turned off to stoposcillation of the plenum boxes 27 and 27 and the cylinder 48 isactuated to shut off the air. The sheet of glass is taken from thecarriage 17, a new one is installed, and the carriage 17 is rolled toits position over the fingers 24 of the lift structure 21. The liftstructure is actuated to raise the sheet of glass into the furnace toheat, following which it is again lowered to bring the sheet of glassbetween the plenum boxes 27 and 27'. The cylinder 48 is actuated to turnon the air, the motor 82 is energized and the cooling cycle is repeated.7

It will be apparent that the objects heretofore enumerated as well asothers have been accomplished, and that there has been provided ablasthead structure which will automatically center a sheet of materialbetween opposing blasts of fluid directed at opposite sides of thesheet.

While the invention has been described in considerable detail, it is notthe intention that it should be limited to the particularembodimentshown and described, and it is desired to cover hereby all noveladaptations, modifications, and arrangements thereof which come withinthe practice of those skilled in the art to which the invention relates.

I claim:

1. A blasthead structure for cooling a vertically disposed sheet ofglass or the like comprising: a pair of spaced apart opposing blastheadsfor receiving a vertically disposed sheet therebetween, each blastheadincluding an end wall facing a like end wall of the opposite blasthead,a plurality of spaced nozzle members extendin-g outwardly a substantialdistance from each end wall toward the other end wall, each nozzlemember directing fluid toward the other end wall, weir portionsextending outwardly from each end wall toward the other and spaced fromand surrounding a plurality of said nozzle members so as to define acompartment facing the opposite blasthead whereby the fluid that flowsthrough said nozzle members to impinge a sheet will flow back to thecompartment where the fluid flow is restricted between the sheet and theweir portion to provide a back pressure among and around said nozzlemembers to center the sheet between said blastheads, and exhaust meansexteriorly of the compartment for receiving the fluid therefrom.

2. A blasthead structure as set forth in claim 1 wherein each blastheadincludes a plurality of spaced end walls with the space therebetweendefining said exhaust means.

3. A blasthead structure as set forth in claim 2 wherein said exhaustmeans are elongated horizontal exhaust openings between verticallyspaced end walls.

4. A blasthead structure as set forth in claim 3 wherein said weirportions interconnect adjacent nozzle membets.

5. A blasthead structure as set forth in claim 5 wherein in said nozzlemembers are arranged in horizontal and vertical rows, spaced horizontalrows of nozzle members being interconnected by horizontal weir portions,at least some of said vertical rows being interconnected by verticalweir portions.

6. A blasthead structure as set forth in claim 5 wherein the verticalweir portions of said vertical rows terminate in spaced relationship tosaid horizontal weir portions.

7. A blasthead structure as set forth in claim 5 wherein each end wallis associated with a plenum section and including a plurality of nozzlemembers disposed in said exhaust openings and interconnecting adjacentplenum sections to provide passages for conveying fluid from theadjacent plenum sections toward the opposite blast head.

8. A blasthead structure as set forth in claim 5 wherein said opposingblastheads are mirror images of one another.

9. A blasthead structure as set forth in claim 1 including means fortranslating said pair of blastheads in unison in plane's generallyparallel to the sheet therebetween.

10. A blasthead structure as set forth in claim 1 wherein each blastheadincludes a plurality of spaced end walls with the space therebetlweendefining said exhaust means, each end wall being associated with aplenum section so that each blasthead includes a plurality of spacedplenum sections, a plurality of nozzle members disposed in the exhaustspace between adjacent plenum sections and supported by adjacent plenumsections for conveying fluid from the adjacent plenum sections towardthe opposite blasthead.

11. A blasthead structure as set forth in claim 1 wherein each blastheadincludes a plurality of said compartments, said exhaust means comprisingexhaust openings disposed between certain of said compartments so thatfluid flows through said nozzle members to impinge a sheet at arelatively high velocity and returns to flow between the nozzle membersat a relatively low velocity and to a weir where the fluid flowsthereover at a velocity higher than said low velocity for providing theback pressure in each compartment to center a sheet between theblastheads.

References Cited UNITED STATES PATENTS 2,263,679 11/1941 Ferre -3483,223,500 12/1965 Mission 65-182 FOREIGN PATENTS 953,953 5/1949 France.

DONALL H. SYLVESTER, Primary Examiner.

S. LEON BASHORE, Examiner.

A. D. KELLOGG, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,353,946 November 21, 1967 Ha ld McMaster It is certified that errorappears in the above identified patent and that said Letters Patent arehereby corrected as shown below:

Column 4, line 54 for l p ate read plates column 7, l1ne 46, for theclaim reference numeral "5 read 4 line 47, strike out "in", firstoccurrence.

Signed and sealed this 15th day of July 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

1. A BLASTHEAD STRUCTURE FOR COOLING A VERTICALLY DISPOSED SHEET OFGLASS OR THE LIKE COMPRISING: A PAIR OF SPACED APART OPPOSING BLASTHEADSFOR RECEIVING A VERTICALLY DISPOSED SHEET THEREBETWEEN, EACH BLASTHEADINCLUDING AN END WALL FACING A LIKE END WALL OF THE OPPOSITE BLASTHEAD,A PLURALITY OF SPACED NOZZLE MEMBERS EXTENDING OUTWARDLY A SUBSTANTIALDISTANCE FROM EACH END WALL TOWARD THE OTHER WALL EACH NOZZLE MEMBERDIRECTING FLUID TOWARD THE OTHER WALL, WEIR PORTIONS EXTENDING OUTWARDLYFROM EACH END WALL TOWARD THE OTHER AND SPACED FROM AND SURROUNDING APLURALITY OF SAID NOZZLE MEMBERS SO AS TO DEFINE A COMPARTMENT FACINGTHE OPPOSITE BLASTHEAD WHEREBY THE FLUID THAT FLOWS THROUGH SAID NOZZLEMEMBERS TO IMPINGE A SHEET WILL FLOW BACK TO THE COMPARTMENT WHERE HEFLUID FLOW IS RESTRICTED BETWEEN THE SHEET AND THE WEIR PORTION TOPROVUDE A BACK PRESSURE AMONG AND AROUND SAID NOZZLE MEMBERS TO CENTERTHE SHEET BETWEEN SAID BLASTHEADS, AND EXHAUST MEANS EXTERIORLY OF THECOMPARTMENT FOR RECEIVING THE FLUID THEREFROM.